Single phase alternating current permanent magnet motors are widely used in electronic apparatus for driving electronic apparatus, such as cooling fan of computer, drain pump of washing machine, and the like. Referring to FIG. 1, a single phase alternating current permanent magnet motor may include a rotor. The rotor includes a rotor core 1 and a rotor magnet 2, which includes a north pole 21 and a south pole 22. The single phase alternating current permanent magnet motor may further include a stator core 3, and a winding (FIG. 1 illustrates an input end 41 and an output end 42 of the winding). A hall unit 5 is disposed adjacent to the rotor magnet 2 for determining position of the rotor accurately and reliably.
To install the hall unit 5 to a predetermined position, a plurality of additional fixing accessories may be used. The plurality of the additional fixing accessories and the hall unit 5 may occupy extra spaces in the motor, which may increase cost and volume of the motor, and further reduce reliability of the motor.